This invention relates to an apparatus and method for improving the awareness of vehicle drivers by prompting the vehicle driver when it is determined that the awareness of the vehicle driver is decreasing due to the vehicle driver falling asleep.
Recently, as a result of road network improvements and more people spend a considerable amount of time driving. In general, drivers tend to drive their vehicle regardless of whether they are tired. If the driver operates the vehicle for an extended time without rest, fatigue sets in, which leads to decreased awareness of the driver and therefore, the possibility of an accident occurring increases.
To prevent this, various types apparatus for improving the awareness of vehicle drivers have been proposed which estimate the state of awareness of the driver according to the driver's heartbeat rate and the driver's manipulation of the steering wheel.
A prior art apparatus for improving the awareness of vehicle drivers which estimates the state of awareness of the driver according to the driver's heartbeat rate utilizes the close relation between heartbeat rate and state of awareness of the driver wherein the heartbeat rate of the driver is almost constant value over an extended period of time when the driver is fully aware and estimates the awareness of the driver according to variations of the driver's present heartbeat rate relative to the heartbeat rate when the driver is fully aware.
Further, a prior art apparatus for improving the awareness of vehicle drivers which estimates the state of awareness of the driver according to the driver's manipulation of the steering wheel recognizes that a small steering period of the steering wheel occurs when the driver is fully aware and the steering period of the steering wheel increases as the driver becomes less aware. The apparatus detects a specific steering period from the driver turning the steering wheel right and left the steering wheel and estimates the driver's awareness from the detected steering period.
Japanese Patent Publication Laid-open (Japanese OPI) 56-2227 discloses an apparatus for improving the awareness of vehicle drivers which generates a preliminary warning when a monotonous driving condition is detected, and a true warning is output when the driver's reaction time exceeds a predetermined time, thereby determining the driver's awareness in two steps.
Further, Japanese OPI 5-3921 uses stimulation instruction means which varies the stimulation degree according to the awareness of the driver.
Japanese OPI 56-2227 determines the awareness of the driver in two steps, and the fact that a decrease in the driver's awareness varies over time is not considered.
Therefore, there is a danger that when the driver continues driving after a decrease in awareness is detected, for example, by outputting a preliminary warning, the driver's awareness cannot be determined more accurately, and an appropriate warning cannot be output according to the awareness of the driver.
Further, in the prior art apparatus disclosed in Japanese OPI 5-3921, the stimulation degree to the driver is varied according to the awareness of the driver, but the patent does not disclose a stepwise stimulation of various human senses. Therefore, the prior art apparatus cannot alert the driver as to the level of awareness, and is thus insufficient in the effect of improving the awareness of the driver.
A primary object of the present invention is to provide an apparatus and method for improving the awareness of vehicle drivers which generates different warnings depending on the level of the driver's awareness which is not affected by individual differences between drivers.